Looper mechanism for sewing machines



'Ju ne 24, 1930. J, BERGER 1,768,103

LOQPER MECHANISM FOR SEWING MACHINES Filed May 4, 1928 5 Sheets-sheaf. 1

'gwtwntoz June 24, 1930. J, BERGER 1,768,103

LOOPER MECHANISM FOR. SEWING IACHINES F e y 1:928 5 Sheets-Sheet 2 June 24, 1930.

J. BERGER LOQPER MECMANISM FOR SEWING MACHINES Filed y 1928 5 Sheets-Sheet 3 T. F F M Wm QWQ QQ ww June 24, 1930. v J. BERGER 1,768,103

LOOPER MECHANISM FOR SEWING MACHINES Filed May 4, 1928 5 Sheets-Sheet 4 June 24, 1930.

J. BERGER LOOPER MECHANISM FOR SEWING MACHINES Filed y 1928 5 Sheets-Sheet 5 I w 6 I I 4 J4 JJ gmwnfot attozmq Patented June 24,-, 1930 l "UNITEDATE P TEN? aosnrn rnncna or U'IICA, NEW YORK, ASSIGNOR T0 with srncmrl MACHINE" by" -1,7 s,1a3

COMPANY, or CHICAGO, ILLINOIS, A CORPORATION oar-primers Iioorim MECHANISM roa SEWING ACHINES Application filed May 4,

improvements in a looper mechanism for sewing machines andmore particularly to a looper mechanism forasewing machine hav-' ing a cylindrical worksupporting arm containing a feeding mechanism for feeding the material lengthwise of the .arm during stitchin An ohject a machine of the above type with .a looper operating mechanism wherein the looper has two motions only, a forward movement into the needle-thread looper, and a retracting movement out of the needle thread loop, both of which movements are in a plane containing the line of feed. v h

A further objeot' of the invention 18 to provide a machine of theabove type with a loop spreader which is mounted foroperation in aline at-right angles to the path of movement of the loopers. a

a A further object ofthe invention is to provide a'looper operating mechanism of the above type which may be mounted in a work supporting arm which, in turn, is suspended from the main frame of the machine and'actuated by an eccentric on a main shaft in the main frame. y

A still further object of the invention is .to provide a machine of the above type wherein the loop spreader is also operated by a train of mechanism in turn actuated by an'eccentric .on the main shaft.

'A further object of the invention is to provide a machine of the above type with a looper operating mechanism wherein the looper is given a relatively short movement and a quick movement into the needle thread loop where it is given an'appreciable dwell.

Theseand other objects will in part be obvious and will in part be hereinafter more fully disclosed.

,In the drawings which show by way of illustration one embodiment of the invention:' I

Figure l is avplan view of one type of sewing machine embodying the invention.

- Fig. 2 is a front view partly in section of the same.

of the invention is to provide 928, Serial No. 275 085. p v

Sis a side view of the *operating mechanism within the work. supporting arm, the work supportingarrn being shown in broken lines. i

Fig. 4 is a. through a portion of the 1 work supporting arm showingthe partsfwithin in plan view. Fig. 5 'is'a planview of'the parts beneath the line 5-5of Fig.3. I i r 1 .6 .is' a view partly in sectionl'a-nd: partly inend elevation .of the worksup-1 porting arm showing particularly the loop spreader in side view. j "i Fig. 7 is a'view similar toFig. 6 but showingadiflerent position of the loopspre'ader;

' Fig. 8 is a perspective view of the carrier for'the loop spreader and showingwa portion. of the shank of the 'loopspreader;

F'g. 9 is a diagrammatic :view of the loopers and spreader showing the looper thread'loops spread for the-needles to enter.

Fig. 10 is a side view of the parts'shown' in Fig. 9'. 1 1: 1 v

The invention is directed. to a loope'r mechanism for sewing macl1ines,'and more particularly toa sewing. machine which has horizontal: sectional view a cylindrical work supporting arm containing a feeding mechanism: for feeding the material longitudinally of the arm. Thelooper mechanism includes a-thread carrying looper mountedzi on a looper'carrier which, in turn, is sup orted atthe free end of the work supporting. arm'so 'thatthe looper may freely oscillate vin a vertical Cal mainv shaft. The connection between the two rock shafts and the connection between v porting arm which is oscillated by a link connected, to arock shaft at the rear end -of the arm, and the rock'shaft at the rear the link 'and first named rock shaft are so formed as to movethe looper'qui'ckly into the needle thread-loop and give an appreciable dwelli at the forward end of its stroke;

. .-If two lines'of stitching are desired, then two needles are used and two -loopers-provided which cooperate independently with the needles; Cooperating'with the loopers is a loop spreader. This loop ;sp reader is mounted on a support which slides along a stationary bar arranged in a line at right angles to the plane a of Oscillation of the: This loop spreader-cooperates with" both loopers when two loopers are used, and p to this end, is provided with two shoulders loopers.

or hooks onthe under face 'ofthe' spreader. The. spreader overlies the loopers and 1s timed so that the shoulders engage the looper' threads of the respective loopers with which they cooperate and move the thread away from the body of the loopers so as to insure that the needles will pass between the thread and the 'looper.- This loop spreader is moved laterally of the loopers by a rock lever located adjacent thefree end of the work supend' of the arm is, in turn, operated by an eccentric-on the main shaft. All of these actuating parts are; so mountedvin the work supporting arm that the arm may be do tached from the main frame with the as sembled parts therein, except for the eccentrio members on the actuating shaft. e Referring more in detail to the draw ingstf The invention 1s shown as applied to a sewing machlnewhlch includes a main supportlng frame learned at the upper outer I end o-fan overhanging bracket 2 which is supported on a ibase3; Extending lengthwise of this main frame l'is a main actuating shaft-4E. The main actuating shaft 4 is driven by a suitable belt wheel-5 and the "shaft also carriesa hand wheel 6 at the outer end.- 'Mounted on this frame and pro- 'jecting'forwardly therefrom is a housing '7 1n-wh1ch a needlebar 8 is mounted for re I clpr'ocation. This needle bar carries the needles of the stitching mechanism. 1 As shown 1n the drawings, there are two needles 9'and 10 mountedon'said needle bar; This needle' bar is reci'procated by a suitable mechanism from the main shaft 4-.

At the opposite end of the main frame 1 from the housing 7 is adependingmember or ;housing 11. Atthe lower endlof this depending member and closing the same is a detachablework supporting arm12. This Work supporting arm 12 is whatis' usually referred. to as a cylindrical worksupporting arm which is especially adapted for stitching tubulararticles; The-work supporting arm 12 is suspended by this depending member 11 and the material maybe passedunderneath the same and folded around-ontothe upper face of the arm andthusjled' to the stitching mechanism. As ,shown 1n *the' drawings, the machine isprovided with a In front of the fpresser footfis' a felling folder 1 5 for interfolding theedge portions of the fabric sections. The material is fed off'the end of the work supporting amt- 'afeed dog 16 carrie d a'feed bar 17. The feed her l7;at its rear end is forked and is mounted to "slide ona supporting pin 18 carried by an oscillating rock frame 19.

This frame 19 is oscillated by means of a link=20 connected toa ball crank2l which in. turn is oscillated by an eccentric" strap 22ccooperating with an eccentric23 on the presser-fo-ot '13 Vcarriedby a presser bar 14. v

main shaft 4. Theswinging frame 19.1:

connected by a link 24 to the feedbar. This imp arts endwise movements to the feed bar.

The feed dogis-raised and lowered by means of a lever 25 carrying a link 26 which is-at tached to the feed bar and this lever 25is V oscillatedby an eccentric strap 27 cooperat ing with an eccentric28 on the main shaft 4:. The feeding mechanism forms no part of the present invention, and is shown described and claimed in my copending appli-V cation Serial No. 276,783, filed May 10, 1928. Cooperating with the needle 9 is a; looper 29 -and cooperating with-the needle 10-is a looper 30. These loopers. are mounted on a looper carrier 81 and the looper carriervis clamped to a supportingshaft 32 mounted to oscillate in suitable bearings 83and-34 carried by the work supporting arm; This shaft oscillates freely in its bearings but has no endwlse movement; and; therefore, the

loopor carrier oscillates in a vertical plane containing the line of feed. Y The loopers are, therefore, two'motion'loopers and have a forward movement into their respective thread loops and a of the same. c H

Thelooper carrier is oscillated'by means of a link 3oiwhichis' pivoted atone end to the carrier and is pivoted at its otherend to acrank pin, 36 carried by a rock shaft 37. Thisirock' shaft is provided with an 0 arm 38. Mounted-adjacent therrockrshaft 37 is asecond rock shaft 39.-' This rock retracting movement out shaft carries an arm-40 whichis'connec'ted by means of a link 4-1. to-the ar1n38 mounted on the rock shafti37. ,The rock shaft 39 also 37 moves from a position which is substantial ly i-vertical 'when th'e loopers are at the rearward end of their stroke. to a position which is substantially horizontal when the.

loopers, areat' the forwardend of their stroke. As a result the horizontal movements imparted to the link 35 andthe for wardmovement thus impartedtothe loopers will decrease in speedas the looper 'moves into the needle thread loop. The arm {10 and link 41 are. more nearly in-alignment when.

the looper is at the forward end of its. stroke than when the looper is at the rear endof its stroke. This, together'with the position of the eccentric on the main shaft, enables the looper; to be. given an appreciable dwell. when it reaches the forward end of its stroke,

and thus itf-is that the length of stroke of the looper may be made relatively short which is another, contributing factor to a. As noted above the high speed-machine. looper has no lateral movement but merely moves back and forth in a single plane and I this is a third contributing factor toa high speedv machine wherein there is comparativelyi little, vibration incident to the rapid movement of the parts. A

Inasmuch as theloopers have no needleavoidingmovement a loop spreader is necessaryin' order to position the looper thread loops for the needles to enter. The loop spreader is indicated atv s8. This loop spreader is mounted on a support 49. The support 49 is carried in part by arod 50 to which it is attached by means of a set screw, and in part by the looper supporting shaft 32. I The support for the loop spreader has a forked end which straddles this loop supporting shaft. This prevents the support for the loop spreader from turning aboutjthe axis; of the supporting rod 50. T he rod-50 is moved endwise by a bell crank lever 51 said lever being pivoted at 52, and provided witha forked end which straddles a pin 58 carried by the rod 50. When the bell'cra-nk is oscillated it will impart an endwise movement to the rod 50 and this will impart tothe loop spreadercarried thereby a movementin a line at right angles to the plane of oscillationof the loopers; The loop spreader is provided with a shank portion 54: which extends into' a supporting socket carried by the loop spreader support and is held therein by a set screw 55." The loop spreader at theupper portion thereof-is bent so as to be positioned in a, line at right angles to the longitudinal axis of the supporting shank 54. This right angle portion 56 of the loop spreaderoverhangs the loopers. The feed dog 16 is provided with an opening 57 through which theportion 56 of the loop spreader projects and operates. On the-under face of the loop spreader there are two spaced shoulders or fingers 58 and 59. These shoulders are so positioned that when the loopspreader is moved laterally the-looperthread a of the looper 30 is en.-

gaged by the shoulder 58 while thelooperthread Z) of the looper29 is engaged'by the p shoulder59.

- As clearly shown in Fig.9thismovement of the loop spreader carries the shoulders into engagement with the threads of the;

loopers and-causes the threadsof the loopers to be deflected away from the body ofthe loopers so that the needles '9 and 10 may enter their respective looper threadloops.

The strand of the looper thread loop which is engaged by the shoulders is the strand of the loop running from the eye of the looper to the previous stitch, and therefore, when the loopers are retracted,a-looper thread loop, will be left about each needle. 7

'The bell: crank; lever 51 is oscillated by means of a link 60. nected to a ball stud 61 carried by anarm The link 60 is con-' 62seoured to a yoke member 63, which yoke member is mounted'forf free oscillation on the shaft '39. Attached to this yoke member is an armcarrying a ball stud 64:. An'

eccentric strap 65 cooperating with the 'ec- Y centric member :6 on the main shaft 4 oscillates the yoke and through the yoke moves the link v61 endwisef. This endwise movement of the link will oscillate the bell crankand the bell crank will, in turn move the loop-spreader back and forth. The loop spreader has only two motions which are back and forth in the direction of its length and said spreader is timed so as to accomplish the spreading of the looper thread loops 1n the manner above stated.

It will benoted that the operating parts I for the loopers and the spreader except the eccentric-members carried by the main shaft are all mounted in the work supporting arm which is capable of being detached from the depending member let. Thus it is that these parts may be assembled in the work supportingarm and the arm afterwards attached to the dependingmember. This greatly facilitates the assembling of the parts of the machine.

It willbe noted from the above description that I. have provided a looper operating mechanism having a suspended .work supporting arm which consists of few parts,

allof which are positively actuated so that the machine maybe operated at very high speed with comparatively little resulting vibration. Mountedonthe looper carrier is a rearwardly projecting plate 66 provided withthread guiding slots 67, 67. The

ion

tance Tabove the a thread' guiding: slots 67 1 whenj'the loopersare clear back and these threaclguiding slots move outwardly and" downwardly away from thethread guiding eyes 68 so asto pull upon the looper thread 1 as the loopersfreachthe rearendof their str'olresf It'is at, this time thatthe loops are being drawn up which have been concatenated vto-form the stitches. r

It is obvious that minor changes inthe details of construction and the arrangement ofthe parts may be made without departing from the spirit of the 1nvent1'on as set' forth in the appended claims. 7 I a Having "fully described 'my' lnventlon what I claimasnew and desire to secure by Letters Patent, is

f 11111 a sewing machine a work supporting arm, means for feeding the material lengthwise ot' tne arm, a looper, means disposed at the free end of the arm for supporting said looper for oscillation in a fixed vertical plane parallel with the feed, and a" loop spreader movable in a fixed path at right angles "to the plane of" movement of the looper for engaging the looper thread 'and' positioning the-same so that the needle will pass into the looper thread loop.

In a sewing'machine a worksupport ing arm, means for feeding the material lengthwise of the arm,a looper, means dls posed at'the .freeend of the arm for supporting said looper for oscillation in a fixedvertical plane parallel with the feed, and

' porting said looper for oscillation in a fixed vertical plane parallel with the feed, a loop spreader, a support for the loop spreader movable transversely of the plane of'movement of the looper, and means extending lengthwise of the arm for moving'said support endwise; V

4. In a sewing machine a work: supporting arm, means for feeding themateriallengthwise of the arm, a looper, means disposed at the-free 'endof thearm for supportlng saidlooper for oscillation in a fixed vertical plane'parallel with the feed, and in a direc tion opposedto the direction offeed when enterin the needle thread loo) a loop b w r i 7 A spreader, 'a support vtor said loop spreader movable endwise in a'direction at right angles-to the plane of oscillation of the looper, and means extending lengthwise of W158. U a r p 6. In a sewing machinela work supporting '5 In a sewing machinea wise ofthe arm,fa looper, means disposed at the free-end of the arm for-supporting said'loope'r for oscillation in a'fixed vertical" plane parallel with thefeed, a loop spreader,-

a' support "therefor disposed at the flfree end of the arm and movable at right angles to;

the'plan'e of oscillation of the looper, and means extending lengthwise ofthe' work supporting arm for supporting arm, means for feeding the material lengththe "work supportingarm formoving'said support endw'l'se.

moving said support end arm, means for feeding the material lengthwise of the armya looper, means disposed at the free endv ofthe arm for supporting said looper for movement in a' 'fixed plane paral- V lel with the feed, 'a'loop spreader, a rod mounted for endwise reciprocation at'the" free end of the work supporting arm inia dlr'ection at right angles to theplane 0']:

oscillation of the looper, a support 'for the spreader attached; to said rod, means for moving the rod endwlse for causing the loop spreader to engage'the looper thread-and position the, same so that the needle will" pass into thelooper threadloop.

" 7. In a sewing machine a work supportingarm, means 'for feeding the material lengthwise of the armya looper, a{-looper carrier,

vashaft on which said looper"carri er1's mounted, said Qshaift being disposed at' the free end of the work supporting armandin a line at right angles-to the line offeed,

means for oscillating said shaft so as to move the looperback and forth in a single plane parallel with the feed, a loop spreader movable in a fixed path'at rightangles with the planeof movementfwiththe-looper for,

engaging the looper threadand positioning V the looper thread loop;

the same so that the needle will pass into 8.- Ina sewing machine awork supporting" arm, means for feeding the material length- Wise of the arm, a'loop'er, aloopercarrier, ashafton which said looper *carrier is mounted, said shaft'being disposed at the free end of the ork supporting armand in the-looper back and forth in asing1eplane parallelwith' the feed, and in a' direction o p-' posed to the direction of "feed when enter ing :the needle thread loop, and a loop spreader movablein a'fixedpath at right angles to the Pl&DG Ol; movement of the looper.

- 9. In a sewing machine a work supporting arm, means for feeding th e material lengthwise of the arm, a looper, 'aloope'r carrier,"

a .shaft on whichisaid looper carrier is mounted, said shaft being disposed at the freeend of the work supportingarm and inlme at right angles to the line 'offeed, a meansfor oscillatmg sa djshaft so as to move 5 a line at right angles to the line of feed,

. said support is mounted, said rod being dismeans for oscillating said shaft so as to move the looper back and forth in a single plane parallel with the feed, a loop spreader, a

support for the spreader, a rod on which posed at the free end of the Work supporting arm and movable endwise in a direction at right angles to the plane of oscillation of the looper. v

10. In a sewing machine a work supporting arm, means for feeding the material lengthwise of the arm, a looper, a looper carrier, a shaft on which said looper carrier is mounted, said shaft being disposed at the free end of the work supporting arm and in a line at right angles to the line of feed,

means for oscillatin said shaft so as to move the looper back an forth in a single plane parallel with the feed, a loop spreader, a support for the spreader, a rod on which said support is mounted, said rod being disposed at the free end of the work supporting arm and movable endwise in a direction at right angles to the plane of oscillation of the looper, said support having free sliding engagement with the looper shaft so as to prevent the rod from oscillating. v

11. In a sewing machine a work supporting arm, means for feeding the material lengthwise of the arm, a looper, a looper carrier, a shaft on which said looper carrier is mounted, said shaft being disposedat the free end of the Work supporting arm and in a line at right angles tothe line of feed, means for oscillating said shaft so as to. move the looper back and forth in a single plane;

being movable endwise at the free end of the arm, in a direction at right angles to the plane of oscillation of the looper, means extending lengthwise of the arm for moving said rod, andmeans for preventing said rod from oscillating. v

12. In a sewing machine a work supporting arm, means for feeding the material lengthwise of the arm,-a looper, a looper carrier, a shaft on which said looper carrier is mounted, said shaft being disposed at the free end of the work supporting arm and in a line at right angles to the line of feed, means for oscillating said shaft so as to move the looper back and forth in a single plane parallel with the feed, and movable in a lengthwise of the armfonmOving said rod, said support for the loop spreader having a forked portion having free slidingengage-- :ment with the looper shaft so as to prevent the rod, from oscillating; n v v v 13'..In a sewing machine awork supportshoulder toengage the looperthread, a support for the shank, means'for moving said support whereby the loop spreader ismoved back and forth in a fixed path at right angles, ,to the looper." V

14. In ing arm, means for feeding the material lengthwise ofthe arm, a looper, a looper:

carrier, a looper shaft at the free end of the worksupporting arm and extending at right angles to the line of feed whereby said looper may be oscillated in a fixed plane parallel with the line of feed, a link extending lengthwise of the work supporting arm for oscillating said shaft, a rockshaft havng a crank-to which said link is connected,

said. crank being disposed so as to move toward and from a horizontal position as' the looper moves into and out of the needle thread loop, an arm carried by said rock plane of movement of the,

'a sewing machine a work support shaft, a second rock shaft having an arm, a

link connecting the arms on the two rock shafts and movableftoward andfrom a dead center line when the looper moves into and out of the needle thread loop.

ios

15. In a sewing. machine a supporting H base, an overhanging bracket carried thereby, a frame mounted at the upperouter end of saidbracket, a mainshaftdi'sposed insaid frame, a depending member at one end of said frame, a work'supporting arm suspended by means for feeding the material lengthwise of said depending member,

the arm and off the end thereof, a looper disposed at the free end of the arm and oscillating in a fixed vertical plane parallel with ing throughsaid depending member and lengthwise of said arm for oscillatingsaid looper, and devices extending through said depending member and lengthwise of said arm for moving said loop spreader.

v 16. In a sewing machine a supporting base, an overhanging bracket carried thereby, a frame at the upper outer end of said bracket, a main shaft mounted in saidframe,

a dependingmember carried by said frame at one end of said shaft, a work supporting arm suspended by said dependingn1e1nber, a :late'ral1y projecting housing carried by the other end of said frame, a needle bar mount- 7 7 ed in the housing for reciprocating directly over theiree end of saidarm, means for feeding the material lengthwise of the arm fand ofi the end of the same,- a looper-dis- V posed at the free endof the arm and mov V able in a fixed vertical plane and ina direc- 11 tion' opposed to the feed When entering the needle tl1readloop,,a loop Spreader movable ina'fiXedpath at right angles to the plane of. movement'of thelooper for engaging the loope'r thread and positioning the Same so 4 that the needle ill pass-into the looper thread loop. 1 v- 1 In testimony whereof, I fifilX my signa- 1 vture. I

JOSEPH BERGER," 

